1. Field of the Invention
The present invention relates to processes for preparing liposome compositions.
2. Prior Art
A process to prepare liposome compositions is disclosed in JPN Unexam. Pat. Pub. No. 53-142514 where the liposome compositions which have been formulated and phospholipid, an active ingredient, and adjuvants are lyophilized for stable storage. According to other processes disclosed in JPN Unexam. Pat. Pub. Nos. 57-82310 and 57-82311, freeze-dried liposomes are prepared with no organic solvent and are formulated into liposome compositions by the use of an aqueous medium which may or may not contain an active ingredient.
On the other hand, a process is disclosed in the JPN Unexam. Pat. Pub. No. 58-152812, wherein small unilamella vesicles (hereinafter referred to as SUV) or large unilamella vesicles (hereinafter referred to as LUV) are prepared by dispersing a special phospholipid in an aqueous medium having a specific pH-value.